In recent decades the use of models in science has become one of the most important problems in contemporary philosophy of science. Surely, as it have been acknowledged, this is due to the fact that scientists working in the natural and social sciences are dedicating a considerable part of their work building, formulating, and evaluating different kinds of models. These models are considered a necessary and valuable tool in scientific research.

In the philosophical literature about models there are some crucial questions concerning not only the nature of models, for example, what are models? But also about the relationship between models and the target system, i.e. how do models represent its targets? Another questions are, what relation does the model have to bear to the target and what is the role of conscious users when a model is used to represent something?

The main goal of our research is to provide some answers to these questions by means of the artefactual theory of fictions formulated by Amie Thomasson (1999). Our starting point is that the practice of modelling shares some important relationships with the creation and handling of abstracts objects such as fictions.
We assume that fictions play an essential role in many aspects of science. But, what role could that be?
What contributions could fictions make to understand how the world actually is? Our thesis is that the dialogical pragmatic approach of the artefactual theory of Amie Thomason ((Redmond 2010, Rahman 2011) provide the theoretical resources to answer these questions.

Identity criteria to answer questions like, how to distinguish one model from another?

Attributions of properties. It is necessary to clarify how when dealing with models we can analyze and compare properties, elements and relations attributed to entities that do not have a correlate with the real world.

Metaphysical and ontological commitments. The ontology of models is a controversial issue. Our proyect will help us to know what kind of commitments we are assuming in our models, especially when understanding model systems along the lines of the artefactual perspective, and how these commitments, if any, can be justified.

Truth in model systems. An account of truth in models system it is required to understand some important semantical issues and also claims about the justification on model choosing.